The complexation between poly(
N,
N-diethylacrylamide) (PDEA) and poly(acrylic acid) (PAA) in aqueous solution was studied by viscometric, potentiometric, and fluorescence techniques. It was found ...that an interpolymer complex formed between the two polymers through hydrogen bonding interactions with the stoichiometry of
r=0.6 (
r is unit molar ratio of PAA/PDEA), and the complex formation show the dependence on pH values. The phase behaviour studies showed that the lower critical solution temperature of the PDEA–PAA aqueous solution gradually increased with the increasing of
r from 0.01 to 0.15, until a soluble system in the whole temperature region was obtained, which remained in the range of
r=0.15–0.3. At higher PAA concentrations, when
r is above 0.3, the system appeared phase separation, and almost no temperature dependence was observed. Based on these conclusion and structure characteristics of PDEA and PAA, a model containing only short sequences of monomer residues was proposed for the structure of PDEA–PAA complex.
A three-step column chromatographic method, utilizing CM Sepharose CL-6B, DEAE Sepharose Fast Flow and Sephadex G-75 in sequence, for the separation and purification of thrombin-like enzyme from ...crude venom of Agkistrodon halys pallas was developed. Based on the separation results on lab-scale chromatographic column, this isolation and purification process was amplified according to the diameter of the chromatographic columns used in labscale. It was found that when the amount of the sample loaded on the large-scale columns was 25 times as that loaded on the lab-scale columns, the quality level of the thrombin-like enzyme obtained with the large-scale columns was almost the same as that obtained with lab-scale columns. The relative molecular mass of thrombin-like enzyme obtained was about 33500, and its purity was about 96%. When using this method to isolate thrombin-like enzyme from crude venom of Agkistrodon halys pallas, the total protein yield and total activity yield of thrombin-like enzyme were about 0.3% and 64% respectively, and specific activity was more than 2000 U/mg.
Chinese medicine（CM）decoction placebo is one of the key factors restricting the placebo-controlled clinical trial of CM.In this article,based on the analysis of the difficulties in preparing CM ...placebo,the production requirements for placebo were put forward.Moreover,in accordance with clinical practices,a production method and evaluation process of CM decoction placebo was proposed,to provide a reference for clinical research.
Ensilage is a truncated solid‐state fermentation in which anaerobically produced organic acids accumulate to reduce pH and limit microbial activity. Ensilage can be used to both preserve and pretreat ...biomass feedstock for further downstream conversion into chemicals, fuels, and/or fiber products. This study examined the ensilage of enzyme‐treated corn stover as a feedstock for particleboard manufacturing. Corn stover at three different particle size ranges (<100, <10, and <5 mm) was ensiled with and without a commercial enzyme mixture having a cellulase:hemicellulase ratio of 2.54:1, applied at a hemicellulase rate of 1670 IU/kg dry mass. Triplicate 20 L mini‐silos were destructively sampled and analyzed on days 0, 1, 7, 21, 63, and 189. Analysis included produced organic acids and water‐soluble carbohydrates, fiber fractions, pH, and microorganisms, including Lactobacillusspp. and clostridia were monitored. On days 0, 21, and 189, the triplicate samples were mixed evenly and assembled into particleboard using 10% ISU 2 resin, a soy‐based adhesive. Particleboard panels were subjected to industry standard tests for modulus of rupture (MOR), modulus of elasticity (MOE), internal bonding strength (IB), thickness swell (TS), and water absorption at 2 h boiling and 24 h soaking. Enzyme addition did improve the ensilage process, as indicated by sustained lower pH (P < 0.0001), higher water‐soluble carbohydrates (P < 0.05), and increased lactic acid production (P < 0.0001). The middle particle size range (<10 mm) demonstrated the most promising results during the ensilage process. Compared with fresh stover, the ensilage process did increase IB of stover particleboard by 33% (P < 0.05) and decrease water adsorption at 2 h boiling and 24 h soaking significantly (P < 0.05). Particleboard panels produced from substrate ensiled with enzymes showed a significant reduction in water adsorption of 12% at 2 h boiling testing. On the basis of these results, ensilage can be used as a long‐term feedstock preservation method for particleboard production from corn stover. Enzyme‐amended ensilage not only improved stover preservation but also enhanced the properties of particleboard products.
Mongolian gerbils were exposed to either alpha-ketoglutarate, salicylate, or an 8-kHz pure tone. Cochlear microphonic (CM) was recorded from the round window in response to 68 and 88 dB SPL Gaussian ...noise. A nonlinear systems identification technique provided the frequency-domain parameters of a third-order polynomial model characterizing cochlear mechano-electric transduction (MET). A series of physiologic indices were derived from further exploration of the model. Exposure to the 8-kHz pure tone and round window application of salicylate resulted in different changes in the polynomial parameters and physiologic indices even though the threshold shifts were similar. A general reduction of CM magnitude was found after the tone exposure, and an increase at low-mid frequencies was demonstrated in the salicylate group especially at the lower signal level. The slope of the MET curve was reduced by the acoustic overstimulation. The root or the operating point of the MET was shifted in opposite directions after the two treatments. Sound-pressure levels that saturate MET expanded in the tone exposure group and narrowed in the salicylate group. The signal level also had effects on these indices.
A new type of photovoltaic system with higher generation power density has been studied in detail. The feature of the system is a V-shaped module (VSM) with two tilted monocrystalline solar cells. ...Compared to solar cells in a flat orientation, the VSM enhances external quantum efficiency and leads to an increase of 31% in power conversion efficiency. Due to the VSM technique, short-circuit current density was raised from 24.94 to 33.7
mA/cm
2, but both fill factor and open-circuit voltage were approximately unchanged. For the VSM similar results (about 30% increase) were obtained for solar cells fabricated by using mono-crystalline silicon wafers with only conventional background impurities.
14-3-3 proteins have attracted much recent interest in the etiopathogenesis of human cancers owing to their involvement in the prevention of apoptosis. However, the expression of 14-3-3 in primary ...nervous system tumors has not been previously characterized. In this paper, Immunohistochemistry using a specific anti-14-3-3 antibody was performed on formalin-fixed, paraffin embedded archival tissue from 124 primary human nervous system tumors and 10 normal brain tissues. In the normal control brains, 14-3-3 immunoreactivity was localized mainly in the neuronal somata and processes, and some glial cells showed only weak immunoreactivity. However, 14-3-3 immunoreactivity was seen in the majority of astrocytomas grade I (9/11), II (16/21), III (13/17), IV (17/21). There was no difference between the positive expression rates of 14-3-3 in different grades of astrocytomas (P = 0.968). But the intensity and degree of 14-3-3 immunoreactivity in diffuse astrocytomas, anaplastic astrocytoma, and glioblastoma multiformes showed trends with tumor grade, with glioblastomas having the highest positivity (P = 0.048). The 14-3-3 immunoreactivity was also seen in the majority of other gliomas oligodendroglioma (2/3), anaplastic oligodendroglioma (4/4), ependymoma (1/2), anaplastic ependymoma (2/2), choroid plexus papilloma (3/3), pineocytoma (2/2), medulloblastoma (5/8). All meningiomas syncytical (3), fibrous/fibroblastic (4), angiomatous (4), transitional/mixed (3) were intensely and diffusely positive. All schwannomas (4), neurofibromas (2), pituitary adenomas (6) and craniopharyngiomas(4) also showed intense positive staining. These results showed that 14-3-3 is expressed in the majority of the primary human nervous system tumors. The up-regulated expression of 14-3-3 may be a common mechanism for evading apoptosis in most primary human nervous system tumors, and targeting 14-3-3 may be a novel promising strategy for the treatment of these tumors, especially for malignant tumors.
The stimulatory effect of FMLP 5 nmol.L-1, OAG 25 nmol.L-1 and calcimycin 10 nmol.L-1 on luminol-dependent chemiluminescence (CL) was observed in human neutrophils (Neu). The rest level of Neu ...intracellular free calcium (Cai) measured by Ca(2+)-sensitive probe Quin 2/AM was calculated to be 200 +/- s 19 nmol.L-1. By the addition of FMLP 0.1 nmol.L-1 or calcimycin 0.5 nmol.L-1, the peak Cai increased to 769 +/- 104 nmol.L-1 and 953 +/- 53 nmol.L-1, respectively. Ketotifen (50-300 mumol.L-1) inhibited Neu CL in a dose-dependent manner with activator FMLP. Inhibition was also seen when Neu CL was activated by calcimycin and OAG, respectively. However, ketotifen did not inhibit Neu Cai increment activated by FMLP and calcimycin.
The intrachain and interchain hydrogen bonding of poly(
N-isopropylacrylamide) (PNIPA) and intermolecular hydrogen bonding between PNIPA chains and the solvent molecules in the mixed solvent of ...methanol and water have been quantitatively investigated by using Fourier transform infrared (FTIR) spectroscopy at 25
°C. In this spectroscopic system with curve fitting program, we found that in the C–H stretching region, both the
N-isopropyl group and the backbone underwent conformational change upon the solvent composition. An analysis of the amide I band suggested that the amide groups of PNIPA were mainly involved in intermolecular hydrogen bonding with water molecules, and the polymer chains were flexible and disordered in the mixed solvent when the methanol volume fraction (
χ
v) was lower than 15%. While
χ
v was in the range of 15–65%, about 30% of these intermolecular hydrogen bonding between the polymer and water were replaced by intrachain and interchain hydrogen bonding, consequently, PNIPA shrinked as aggregates. If
χ
v was above 65%, the interchain hydrogen bonding became predominant due to the solubility characteristics of amphiphilic methanol, and the PNIPA system was homogeneous solution again. We believe that the reentrant transition is related to the weaker interaction between PNIPA molecules and methanol–water complexes, (H
2O)
m
(CH
3OH)
n
(
m/
n
=
5/1, 5/2, 5/3, 5/4, 5/5) as compared to that between PNIPA and free water or free methanol.
The brown planthopper (BPH), Nilaparvata lugens Staal, which is one of the most destructive pests of rice, has been confirmed to harbor yeast-like symbiotes (YLS) in the fat body. Several ...morphologically different YLS have been previously isolated and cultured in vitro from BPH, but direct evidence is lacking to further clarify whether the cultured YLS were from BPH. In this study, one species of YLS was successfully cultured in vitro and simultaneously verified to exist in the fat body of BPH by sequence analysis and nested polymerase chain reaction (PCR). The cultured YLS isolate in vitro was identified as a member of the genus Candida on the basis of 18S rDNA (ribosomal DNA) and 5.8S-ITS (internal transcribed spacer) rDNA sequence and a phylogenetic analysis of ITS sequences from yeast. Therefore, this yeast isolate was named as Candida-like symbiotes. Candida-like symbiotes was found to exist in fat bodies, ovaries and newly laid eggs of the BPH, but not in the heads, thoraxes and mid-guts. In addition, the number of Candida-like symbiotes in 1 x 10 super(6) of purified YLS from BPH fat bodies was speculated to be (5.32 plus or minus 0.22) x 10 super(4) on the basis of a quantitative PCR analysis.
